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Interview of Gerson Goldhaber by Ursula Pavlish on 2005 June 22, Niels Bohr Library & Archives, American Institute of Physics, College Park, MD USA, www.aip.org/history-programs/niels-bohr-library/oral-histories/34508-1
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Gerson Goldhaber (1924- ). Early training at Hebrew University in Jerusalem (1942-1947). Graduate work at The University of Wisconsin. Research at Columbia University (1950-1953); memories of Rabi. Research at The University of California at Berkeley and at Lawrence Berkeley Laboratory (LBL). Took part in first experiment at Bevatron. Worked on K-mesons, the tau and theta mesons; measured the radius of interaction, and the difference between the behavior of like and unlike pion pairs; contributed to the design effort of SPEAR (Stanford Positron-Electron Asymmetric Ring) accelerator at SLAC; co-discovered, and named the Psi particle with George Trilling; Goldhaber found the naked-charm mesons; with colleagues, measured the lifetimes of a number of particles, including the tau lepton, the D mesons, and the B meson; at SLC (Stanford Linear Collider) did measurements of the mass and width of the Z particle, measuring how much of the Z decay went into neutral leptons. With colleague Robert Cahn, he wrote and published the textbook “The Experimental Foundations of Particle Physics.” Part of The Supernova Cosmology Project (SCP) since 1989. 2004, ‘Gersonfest’ held in his honor.
Good, so what would you like to discuss?
I’ve prepared a little introduction and I’ve prepared ten questions for this afternoon.
Ok, something to get started. By the way, I don’t have too much time this afternoon. I probably have to leave by 5:30.
Ok, that’s perfect.
It is Wednesday, June 22, 2005. We are sitting in Dr. Gerson Goldhaber’s office in the Lawrence Berkeley National Laboratory in Berkeley, California. This is Ursula Pavlish speaking and I’m here today to interview Dr. Gerson Goldhaber. Dr. Goldhaber is a particle physicist with a distinguished career spanning over half the twentieth century and recently Dr. Goldhaber has pioneered particle astrophysics studies. The scientific projects led by Dr. Goldhaber have been of the greatest value. Moreover, Dr. Goldhaber’s life in physics is itself a remarkable phenomenon. As one of the organizers of Gersonfest — a symposium held last year in honor of Dr. Gerson Goldhaber’s 50 years at Lawrence Berkeley National Laboratory (LBNL) and in celebration of his 80th birthday — noted, there have been phase changes in Dr. Gerson Goldhaber’s career corresponding to different experimental techniques. Both the physics that Dr. Gerson Goldhaber has discovered and his extraordinary life in science deserve abundant attention as they exemplify the nobility and meaningfulness of the human enterprise. That is why Dr. Gerson Goldhaber and I are here today: to discuss his unique perspective, his life and work in physics.
Ok. Most of that is ok.
I go to my first question now. With my first question, Dr. Goldhaber, I would like to lead you back in time, to your childhood and youth. I would like to ask, when did you first become interested in physics? What were the major influences in your life that led you to a career in science, and in physics especially?
As a child, I used to enjoy building things. At a very early stage, it was just putting some nails in a piece of wood. But later on I built various types of apparatus. I built an apparatus to measure g by some interesting technique and things of that sort. I got hold of a book, “The Boy Electrician,” I forget by whom it is. I did many of the experiments. I built a motor, I built electroscopes, and so forth. I enjoyed building things. One of my main influences was the fact that my older brother, Maurice Goldhaber, was a physicist. I heard about various things he worked on and got interested in the field. He certainly influenced me in going into this field. He also, quite early, encouraged me. He wrote down the ideas I had of how I would like to build something. He made notes of those. But then we were separated. I was born in Germany. We left when I was 9 years old due to the Nazi regime. It was my father who had the good sense to leave early. ‘33 was quite early to leave. At that time, we went on to Egypt. My parents and I and one older brother went on to Egypt. But Maurice went on to Cambridge, England, and from there he went to the United States. He got a professorship at the University of Illinois. I didn’t see him for about 17 years, till I came to the United States. That was the war years. It wasn’t easy to travel and in those days unless one was very rich, one didn’t travel. We were in contact, we corresponded. As I say, I was very interested in what he was working on. Finally, I was going to come to the United States in 1940 when I finished high school in Egypt. But at that point the wisdom of the American government was that since I was born in Germany, even though I was Jewish, they did not want to give me a visa. I went to study at the Hebrew University in Jerusalem where I finished in 1947 with my master’s degree. In the course of that also I met my first wife who was also a student there. We got married in ‘47 and left for the United States soon thereafter. My brother helped me find a position there at the University of Wisconsin, near Illinois, as a graduate student.
He was in contact with physicists already at several universities?
Yes, he was in contact with people. So that’s how I started my physics education.
Your answer leads into my second question about people who influenced you. Did you have exceptional high school physics teachers, college professors at the Hebrew University in Jerusalem and at the University of Wisconsin, mentors at Columbia University or here at Lawrence Berkeley National Labs?
Not really anyone who stands out. I did a master’s thesis at the Hebrew University on X-rays. I progressed in energy, to ever higher energies. I started with Xrays. I did something on X-ray crystallography with Dr. Ernest Alexander. Then I came to Wisconsin and worked with Hugh Richards. He was my professor there. I actually did an experiment which was partially suggested by Maurice, which is to look for gamma rays in photographic emulsions. The technique was to load emulsions with heavy water. I managed to get cc or two of heavy water. I developed that technique of soaking emulsions in various liquids. And that way, I was able to do the photodisintegration of the deuteron. Namely, a gamma ray comes in and the deuteron splits up into a proton and a neutron. The neutron you don’t see. But when you see the proton track in the emulsion you can deduce from its angle and energy, you can deduce the energy of the gamma ray. I called it the world’s most cumbersome gamma ray spectrometer. But that’s what I did for my thesis.
But the first?
Oh, it worked. In the meantime other people developed other gamma ray spectrometers that were much more efficient. It worked fine, but it wasn’t easy to use. Then after my thesis. I should say my wife was a chemist. She studied chemistry. After our son Nat was born, she went back to finish her PhD in chemistry. I went to Columbia as an instructor and she stayed on and finished her PhD. After that, she and my son joined me after another 6 or 8 months at Columbia.
Was it a related group that you went to at Columbia? Did your PhD dissertation advisor recommend someone there?
No. I wrote to many universities. I had the idea that I should continue working with the electrostatic generator as in Wisconsin. In writing to various universities, it was Columbia where I got a position. And I continued there with these photographic emulsions. Although at first, I wanted to abandon them because it was such hard work to scan the emulsions. But later on at Columbia there was an Italian physicist, Gilberto Bernardini who was working with emulsions. He was looking at pions in photographic emulsions. It was such beautiful work that I decided to come back and they had scanners at Columbia. I didn’t have to do all the scanning myself. They had a team of 10 or 12 people who were scanning the emulsions. That made it interesting again to go back to emulsions.
What did it involve to scan an emulsion? What about it was so time consuming?
You have to look through a microscope for hours on end. In the case of the experiment I did, I had to look for these proton tracks. These were single proton tracks. They’re easy to detect but you have to look at a large area of emulsion with a microscope. It is very tedious. So it is not something that I wanted to continue at first.
Because you had a lot of ideas from when you were young. You were always thinking of new…
New experiments and such. I was very excited. I came to Columbia just as they had built a new cyclotron, a 350 MeV cyclotron. So I started working at that. At first I was going to do a counter-experiment with a colleague, Dave Bodansky. But when I saw the work that Bernardini was doing, I decided I would continue with emulsions. There I found an example of an elastic scatter of hydrogen in the emulsion. There is free hydrogen in the emulsion. I was able to find an event, this hydrogen scattering. Then I went back to my old techniques of loading with deuterium. I did an experiment on pions scattering on deuterium. Nobody had done that yet. Then I teamed up with Leon Lederman. We did an experiment which was very ambitious. Fermi was just discovering this 3-3 resonance. Yang had come up with the idea that maybe it’s not a resonance maybe it’s just a different phase shift. So we decided that we could measure the phase shift. These were positive pions on protons. Now if you look at the cyclotron, the positive pions were bent into the cyclotron, the negative pions were bent out of the cyclotron. So it was easy to do experiments with negative pions but hard to do experiments with positive pions because they were bent in. We devised a technique to put photographic emulsions inside the cyclotron, in the vacuum of the cyclotron. In fact, wet photographic emulsions. We had them in a little box. The idea was to measure the phase shift of what is now known as the 3-3 resonance. Well, this was one that got away. We measured two points near the peak of the resonance. But we ended up on two sides of the resonance. We never hit the top of the resonance. As a result we decided…
You didn’t measure frequently enough?
No, we only measured a few energies, three or four energies. Because scanning of emulsions was involved it was a difficult experiment. So we missed the peak, and we decided that maybe it was not a resonance. So we have a paper out, Leon Lederman and I and another person saying we don’t think it’s a resonance. So that’s one that got away.
Close, but no cigar. I spent three years at Columbia in that position. As I was an expert on emulsions, I got an offer. Somebody came to visit from Berkeley. Hugh Bradner came to visit. He was able to offer me a position in the Segrè group here in Berkeley. And I accepted that. I got a position in the group and I got an acting assistant professorship in the department. The reason was that Segrè wanted to build up an emulsion group. When I came, I built up a complete emulsion group with very fancy developing techniques. One had gone over to stacks of emulsions, meaning say 100 emulsions all together on top of each other in a stack. When you find a track you have to follow it from one emulsion to another. I developed such methods for following emulsions and I built a special microscope for doing that.
Was it a microscope that you used only here, or something that other people came and to see and said can we build a similar microscope?
No, we used it. Other people built somewhat different microscopes. But it was very useful. I’ll tell you in a minute. I set up an emulsion group but it was on campus, at Berkeley campus, not up here at the lab. The reason being that in those days one needed a clearance to work at the lab. And for some reason we did not get clearance, both me and my wife. For about a year we did not get clearance. Finally Edward Teller who was a good friend at the time asked about it: why didn’t we get clearance? Finally we got called in for questioning at the FBI about the clearance. Finally, they asked me. There was somebody, who during the war, a third cousin on my wife’s side who was a communist. And actually, apparently was killed during the war. So they asked me about him, I had never heard of that person. So we clarified that. That satisfied them, so we got clearance to work at the lab. I had already built up all the equipment on campus in the meantime since I was an assistant professor on campus. There was a shopman, I can’t think of his name right now, who was very good. His name was Brower. He helped us build this developing facility. It was a whole room full of tanks, of stainless steel tanks for developing the emulsions. We built a lot of equipment for marking the emulsions and so forth. I may still have an emulsion somewhere here.
Is the building where you worked still there on campus?
Yes, yes. But my lab has been taken over by other people.
But the actual room is still there.
The building is still there, yes.
It’s the physics department building?
Yes, yes. Anyway, just as I came to Berkeley the Bevatron started working within a few months. I did the first experiment at the Bevatron. We exposed some emulsions at the Bevatron and were able to show that indeed it had reached 6 GeV as it was designed to. And I have in the notes I gave you, I have some reminiscences on the Bevatron. This is one of the history conferences where I talked. That’s in there. Let’s see. So we started out studying K mesons. We were finding K mesons. They had originally been seen in cosmic rays. We were now finding them at an accelerator. So we studied K mesons. We measured lifetime, we measured masses. We had some evidence that the two types of K mesons, the theta and tau, which were believed to be different had the same lifetime and the same cross section and the same mass. We measured the mass of it. There was another group under Richmond here at Berkeley who, also worked with emulsions, did some extensive experiments on measuring the mass of the K mesons, theta mesons, and tau mesons.
May I just breaking in a sec. When you say we, you were leading a group, or you were working in the Segre group? How many of you were working together?
I was independent. I was in the Segre group but I was leading the emulsion effort.
You had some graduate students, maybe?
I had graduate students. My wife started also after a while, started working. We worked together, starting to load emulsions with different kinds of liquids. That sort of got her from chemistry into physics. She switched from chemistry into physics. We basically worked together. There was one other person from the Bevatron team who helped us, who worked with us, Warren Chupp. Being on campus I had some students.
Graduate students, yes. And we built up a scanning facility. We got some scanners. At the hey-day we had about 20 microscopes and 20 scanners working on this stuff.
So you just hired people to do the scanning, like at Columbia.
Yes, those were just hired for scanning. Some were students, most were just people. We did make a contribution to this tau theta puzzle that finally was solved by Lee and Yang showing that parity is violated. The main thing was the study of the antiproton. Let’s see, maybe we can pick up one of those, also the book will do.
I looked at this in the library. I did read about that. I couldn’t take the book out of the library because unfortunately it is on reserve.
Yes, well now you have one. Let’s see, the antiproton. So around 1955 I was joined by… oh, I also had some visitors from Europe. Stephen Goldsack was an early one. Later on, Gösta Ekspong from Sweden, who is still a good friend. [GG looks in book] Let’s see, where is the antiproton? Anyway, so we started looking at antiprotons. We found one event. The antiproton had been discovered by Segrè and Chamberlain and Clyde Wiegand and Ypsilantis but what they discovered was a negative particle of mass close to the proton. Within 5% of the protonic mass. What we discovered was that this particle interacted and released more energy than the mass of a proton. Usually, if this would be a meson, it could only release as much energy as its mass, E=mc2. But because this is an annihilation it kills itself with another proton or another neutron. That reaction releases more mass, more energy, than the mass of the proton. This event was the proof for it. We found that. It was a funny business. As Owen Chamberlain and Clyde Wiegand were building the antiproton beamline where they had discovered these particles of negative charge and mass of the proton, they just went ahead and called it the antiproton. The proof really came with our annihilation event. We had exposed some emulsions here. That, we exposed just sort of in the... Let’s see do I have a picture of that here? I guess I don’t have a picture here. Oh yes, here it is. We exposed at some higher momentum so that the antiprotons did not stop in the emulsion. The emulsions were just full of junk. It was very hard to scan but one event was found. Actually, it was found it Rome. We made a collaboration with Eduardo Amaldi’s group in Rome which Segrè brokered. I exposed the emulsions, developed the emulsions, and gave half to them. In their half, they found this event which is an antiproton annihilation. However, the energy released was less than the mass of the proton. It didn’t give the proof. It’s the other one which we found here in Berkeley which gave the proof for the annihilation. This was together with Gösta Ekspong who is one of the authors of this article. Ok, so let’s see. Where are we?
That was important for both experimental and theoretical physics, right? Because of for the Dirac equation…
It proved that Dirac was right. And Einstein was right: E=mc2 although that had been seen before. It was the beginning of particle physics. Not quite, there was an earlier beginning. The real beginning was the discovery of the neutron by Chadwick. That was the first new particle. Those are all in my book here. Ah, so this was a highlight in ‘56 when we found it. We had a first exposure, which as I said, was at a higher energy anti-protons which did not stop, so we could only see them when they interacted. Although the one that I showed you probably did stop. It must have been slowed down somehow. The emulsions were very full of junk. So it was hard to find.
When you say full of junk, what does that mean?
Full of all kinds of interactions. Protons came in. There were also protons in the beam. There was no selection. So we learned a lesson from this and then I decided that what we needed was first of all go to a lower energy. Ed Lofgren was the head of the Bevatron. He was very instrumental in getting us to go to a lower energy, lower momentum. We went to an energy so that the antiprotons could stop in the emulsion. The other thing is that I introduced this extra magnet here if you can see it’s down here, just ahead of the emulsion, which selected negatively charged particles and bent away the positive. So there was not so much stuff coming into the emulsion. So that cleaned the beam out. In the other one there was lots of stuff. Oh and, there was another problem with the first exposure. Because it was higher energy, it was around 1 GeV/c antiprotons we were looking for. To slow them down, we put a copper absorber in front. What we did not know, what was not known until later, is that the antiprotons have a larger cross section than the other particles we knew. Because in addition to interacting they can also annihilate. They have twice the cross section we expected. That meant that this absorber killed nearly all the antiprotons. And we didn’t realize that until later. One day Edward Teller came into our lab. He said he knows why we are not finding any antiprotons. That this absorber must be killing them. So it not only killed them, it also produced lots of secondaries which came into the emulsion and so they were crowded with stuff. Ok, so the new thing was then to go to a lower energy antiproton and sweep out the positive particles. And then it was very interesting. The photographic emulsions, so this is like a stack of emulsions. The antiprotons came in through the edge of the emulsion. Now at this momentum, I think it was 700 MeV/c, the pions were still minimum ionizing. The antiprotons were twice minimum ionizing.
Let me just draw this. Here’s the book. The antiprotons are coming in, 700 MeV/c and then...
And as they come in, you can look at them and the ionization is different. The pions are minimum ionizing while the antiprotons were twice minimum at this momentum. So right at the beginning you could see what is a potential antiproton. What we did is just to follow the track. And then the first one we followed is this one and we saw the annihilation. My colleague Gösta Ekspong was scanning and he found it.
What was it like in the lab? Were you together in the lab and he said, look what I found, or…
Yes, we were together. I already knew he was following the track which was potentially interesting. Then he found it and then yes and there was a lot of excitement. Two things happened: Segre got me a telephone. I didn’t have a telephone in my lab. This was important enough so we got a telephone. And the other thing that happened is that my drawing of this event was shown by Chamberlain at a meeting in New York and it ended up in Time Magazine. So my picture was in Time magazine. They didn’t say who found it or who drew it but they did show the picture.
That would have been in ‘56
A Time magazine issue in ‘56.
The reference is in these notes. Ok, so that was the antiproton.
I’m going to turn the tape over now. It’s a 90 minute tape so just to make sure… Testing, testing. I’ll ask the question again then. An organizer of Gerson-fest spoke of phase changes in your career. Do you find this characterization of your career in physics to be accurate? And a follow up to that, when you changed from one experimental technique to another what motivated the change? Was it chance, was it your interests changing, changing technology?
It was the development of technology. I started with emulsions, and then the bubble chamber came along. And that was a better method and so I switched to the bubble chamber. And then after that there were the colliding beams. I formed a group with George Trilling, here at LBL. We were co-group leaders. We were invited by Burt Richter to join an experiment at SLAC in Stanford. It looked like this was a good time to switch. It was totally different techniques. It was a counter experiment. So far we had visual techniques. These were counter experiments but in some sense they became visual techniques also. Now we started looking at images reproduced on the computer. Before that we had direct images, photographic images. And now we started looking at computer reconstructed images. [Pause] But all that was much later. That skips to the 1970s. Then we worked for 20 years with this until the 1990s, the end of 1980s. Then the physics community was building the SSC and all my colleagues who were working with me joined the SSC. I decided that this was going to take ten years before one gets any data. I am interested in the data analysis. And I didn’t want to wait that long. I opted not to join the SSC. I looked around. There was this group which Rich Muller and Carl Pennypacker were running; Trying to look for distant supernova to measure the fate of the universe. Now that appealed to me. And also, that allowed me to again use visual techniques. Only now I looked at pictures from a telescope, instead of pictures of emulsions or of bubble chambers or computers.
Is that a sort of coincidence? Or is there something about the visual techniques…
I like the visual techniques. I gravitate toward the visual techniques. But now it’s the telescope. I have certain skills which I was able to apply. So I decided to join that experiment quite early. They had just started. That’s what developed into the Supernova Cosmology Group. A young postdoc, Saul Perlmutter became the head of this group. It was offered to me but I decided that I had been head of a group for thirty years and I didn’t want to again do that.
Did you choose him?
I helped choose him. It was the lab who decided. It was kind of putting confidence into a rather young person but he seemed very good so it worked out well. That’s another story. That’s when we discovered dark energy.
Can I back up just a little bit to what you said a few minutes ago when you said that you were interested in the data and it would take 10 years for the SSC. Is that because you had this talent for building experimental apparatuses that very often got…
Got data. It wasn’t so much building as it was looking at the data. Data analysis is my specialty. I did build things along the way. In fact, there was this possibility of building a detector for the SSC. That was going to be a ten year building job and I didn’t want to do a ten year building job.
So that part goes back to when you said you were young and you built a way to measure g… you were building it to get the data not just to build it.
Building to get something definite out. It was rather elaborate. I got some prizes in high school. I have at home some books, some pictures of the apparatus.
Do you think you got the prize because yours was the most precise measurement?
No, because I just built this gadget. It started with me wanting to build things but it shifted toward data analysis.
This change in your career, was it because you had always been interested in astrophysics? Is it also that element?
I was interested. This appealed to me: the fate of the universe. We still don’t have it, but we’re on the way.
One of the big stories in physics!
In your over 50 years here at the Lawrence Berkeley National Lab, have you taught in addition to doing research? Have you mentored younger physicists? I know that some of my physics professors back in Princeton like to teach and to do research; others found teaching a distraction from their research.
Definitely. I was a professor in the department and I taught all those years. I had about twenty students over my career.
Yes, graduate students. Lots of undergraduates, I don’t know how many. I liked to work with students. I was teaching as a professor in the department for many years.
How do they do it, did you just teach whatever course was needed or did you have favorite courses?
I had favorite courses. I taught a course on Quantum Mechanics. I taught a course on particle physics, partly a reading course. That’s what developed into this book. I developed the material for this book over teaching it for several years. And of course with my colleague, Bob Cahn. I asked him to join because he’s a theorist. Actually, I have converted him a little bit to an experimentalist. Anyway, we wrote this book together. He is largely working on the second edition now.
People are clamoring for it because it’s not available. Somehow it’s taking a lot of time.
Does it take a long time? It took you years to put together the course. Then, once you had all the materials together for the course how much of a jump was it to do the book?
To write the book? Not much. It took maybe three years to collect the material and write the book. And then, with that material it was not so difficult to write the book. And Bob Cahn likes to type so he typed it himself.
Wow. It is an excellent book. I am looking forward to having it. Next question, what qualities do you find distinguish you as a great physicist? Did you develop these qualities during your career or was it something you were born with? Were you born a scientist, do you think? Was it an inevitable thing, what you feel was your destiny?
I don’t know. I like to enjoy myself and I enjoy doing physics. I think maybe I have a knack for it. At least, I’ve managed to be in many of the important experiments.
When you were in high school, for example, was it definitely physics, versus chemistry or biology or some other science, was it something about physics?
It was physics. Actually, I enjoyed chemistry also. As a child, well while I was in high school I couldn’t afford a chemistry set but I was able to read to see what all the ingredients were and in those days I could just go to the pharmacy and buy them all. I had a complete set of chemicals that were just in a normal chemistry set and I did chemistry experiments for quite a while.
Did you do them by yourself or with your brother?
I did them by myself. With my brother we were not in contact for seventeen years. I did them largely by myself. I did some things. I remember creating hydrogen by plunging a burning coal into water and then collecting the gas that came off, it was hydrogen. I did that together with someone, I forget who it was.
Maybe one of your friends?
With one of my friends, yes. And then we let out the gas and burnt it. I did that at age 12 or so or younger.
Did your parents mind?
They had no choice. They were supportive. In fact at one point, still in Germany we moved from one house to another and there were all these lamps that were there. I was doing electric servicing of those lamps. Only, I wasn’t quite clear that all those little wires had to be kept separate. In working with this, I blew our fuses maybe every day. Finally I learned that I had to keep those little wires separate.
So, it was kind of a given — that your parents let you do that. They knew that you were talented at it.
Yes, they let me. And I always had experiments going in my room.
Really? You had the chemistry experiments and then…
Yes, chemistry and physics. I would have to consult my notes as to what it is I built.
You took notes then or you wrote it down later?
I took notes then.
Really? So you had lab notebooks kind of just for your…
Kind of, yes.
Wow, that’s really neat. I would be interested in that, maybe in another meeting. Or what you find, it depends what we have time for. The next question is, could you talk about what it is like to make great discoveries as you have, of fundamental particles like the Psi 3095 and Psi 3685 particles, charmed particles in particular the D meson as well as the tau lepton and amazing also some of the most distant supernovae ever observed including the most distant at a distance of about 9 billion light years. Whatever you think how to answer. Maybe just a general…
Well, it’s very exciting when you find something, something new. I remember finding the charmed meson. First of all, the Psi was a collaboration between three people here and two people at SLAC, Burt Richter and Martin Perl. It started by Richter asking us to join. They had built this SPEAR, the electron positron collider. But we had this experience of analyzing interactions, analyzing events. Here now the events were computer reconstructed. So, it’s just like in a bubble chamber you have a picture, here we had a computer reconstruction of a picture. Here we had the experience of analyzing those. That is why they invited us to join the experiment.
They didn’t have people as good.
They didn’t have people with this experience. They had experience with building equipment. So we both built equipment. At this point our group, this is Trilling and my group, had three people. Three postdocs; we had Gerry Abrams, John Brown, and one more, John Kadyk. So as a group we joined with Perl and Richter. And then also Willi Chinowsky who was not in our group but was also here at Berkeley and with some students we contributed to the analysis of the data as the data started coming in.
May I just back up a bit? Do you remember exactly how you were asked? Whether you deliberated for a while, whether you said, well is it worth us going over there?
Yes, we did not immediately.
They called you up or?
No, they came and visited. Burt Richter came to visit us and told us about it.
Did you meet in your office?
In my office, yes. We had a brief discussion and then George Trilling and I discussed it with the other people also and we decided that the bubble chamber was sort of past its peak. This looked like a very interesting new direction to go in. So we decided to join. We built some equipment for the detector at SPEAR.
The Mark 1 detector. The SLAC-LBL Solenoidal detector. Later on known as Mark 1 because then we started building a Mark 2. So we undertook to build some equipment. And we built some liquid argon gamma ray detectors. But we mainly worked on the analysis. I mean, the important thing was working on the analysis of the data. The discovery of the psi came about because we had noticed, actually John Kadyk had noticed, that we were plotting the cross section of the electron positron annihilation. One point was about 15% higher than what the curve would have been. And so, and other people agreed with this. In the meantime the machine was being reworked to go to higher energy. We had to convince Burt Richter that we should go back and explore this, why is that point higher in cross section?
You out-ruled that it was just a spurious point.
Yes. Well, I’m actually not saying this right. Marty Breidenbach went back and measured some more data in that region. He confirmed that there was a higher point there. We argued with Burt Richter. He wanted to go on to a higher energy because one had to return the machine to its original form to run it at this old energy. Anyway, we convinced him. One thing that convinced him was that I had found that there seemed to be more K mesons produced in that region, in that data. That was probably a fluke. But anyway it looked that way. And so as a result we decided to go back to try for a weekend to go back and see what’s going on in this region.
Was a weekend enough time to take the energy back?
Yes, we could take the energy back and we started out on the weekend and suddenly we ran into this enormous peak. I was in touch with SLAC and I went over and spent a weekend there and we found this enormous peak, the psi.
And is that the November Revolution?
That’s the November Revolution, yes. This is all detailed in some of the notes I gave you there. You can get more details out of that. Let’s see where is that? We can go into some of the details in a later discussion. Anyway, it was found within one day. I went out there. We found it.
There was champagne?
There was champagne and lots of excitement.
I was reading that other physicists came down to see. You had some champagne. There were so many people coming to see that there wasn’t enough champagne for everyone.
Probably not. I got some. This is the peak we found. This is the psi resonance. All in one weekend.
And when I saw this data coming in, the cross section had doubled. So I went off. It had gone up a factor of seven. So I decided it was time to write a paper. I went into another room, picked up some output from the floor to write on and started writing the paper. And maybe an hour later, Willi Chinowsky came in and said it had gone up another factor of ten.
This was something enormous.
So we had the paper written by that afternoon. That was a very exciting time. I have a whole section on that in those notes.
I will read those and then come back to ask you further questions.
Sure, by all means.
Here is question number seven. According to one historiography of science, ninety percent of science that has ever been done, has been done in the last fifty years. Of course this depends on how you measure what is science, etc. Having led the way in the particle physics and cosmology during this time, how do you feel about this golden age of science? Do you see this continuing into the future similarly as it has, or differently? I mean, it is a Golden age. There’s no doubt about it.
Yes, for sure. It can continue, but differently. Because the energy that’s needed now is so much greater. That these machines become terribly expensive. Once something costs several billion dollars, suddenly there’s a reluctance to build it. So I think the discoveries will continue but they may be of a different nature. Maybe not in particle physics. Well, there’s a big hope now that the Large Hadron Collider at CERN will lead to some interesting data. But beyond that…
With the Higgs Boson?
With the Higgs, yes. Possibly. We don’t know. It’s just a theory.
Do you have any intuitions about the Higgs?
No, I don’t. They’ll have to show whether they can find it or not. But beyond that it’s going to be very hard to get the money to build even bigger machines. So I think that research will continue but it may take a new direction. A lot may go into Cosmology. We’re proposing a satellite to measure the dark energy in greater detail. That’s getting to be an expensive device in Cosmology. I’m sure there will be lots more discoveries. We have only scratched the surface. But they may be, certainly of a different style.
When you were working in particle physics were you at all interested in the other parts of physics, what was going on? Everything was happening in particle physics so…
It was the most interesting field at the time. I was interested, but I wasn’t doing anything else. I wasn’t working on anything else. There were interesting results in atomic physics and so forth. Now there are these quantum dots. My great nephew is at Stanford a Quantum dot expert. We haven’t mentioned that my first wife died in 1965. And then in 1969 I remarried and my wife is a writer. So until that time, my wife Sulamith Goldhaber was working with me. We worked together here at Lawrence Berkeley Lab once we got the clearance. But I have a hobby. My wife Judith and I wrote a book together. She wrote sonnets from the fables of Aesop, and I did the illustrations.
Oh wow. This is beautiful. I did see just a bit of it online.
You saw the website. Yes.
So you are an artist also?
I guess so. Now I am a published artist.
Yes, wow. I would like to buy one of these books.
Ok, sure. You’re very welcome to.
So have you just drawn on your own as a kind of evening pursuit?
I started at age 45. I started drawing. Drawing and sculpting, metal work. All kinds of different art forms.
Before that you hadn’t done any at all?
I don’t know if that’s related. It was after my first wife died that I started.
And you just discovered that you had a talent, a natural…
I don’t know if I have a talent but I can draw.
Were they mostly abstract paintings?
I see here you have, these are yours?
Figurative. Yes, these are mine. Those are mine.
No, they are not abstract. Well this is a bit abstract, yes.
Actually this is something that I’m interested in, the intersection of art and science. Do you ever feel like your painting, like you would think about science in the back of your head while you were painting or was it more of a release, something different?
Something different. Getting away from the science.
It gives your mind a rest.
Do you find that you think about science all the time? Even on the weekends?
No. I used to. I retired from teaching in 1991 and now I take weekends off. I do not work on science on the weekends. So I do drawings instead. Yes. I used to work more on the weekends but after retirement I decided that the weekends are for the family.
Do you, well this is more of a personal question because I myself don’t take many weekends off. Do you feel like it’s right that you worked weekends before and now that you’re retired you take weekends off or do you think it would have been nice to have done this before. Or do you think you couldn’t have done what you did if you would have taken the weekends off.
I would say that occasional weekends were necessary. Even now, when we have data coming in I work weekends. But by and large I like to take the weekends off. I used to take vacations. I didn’t work all the time. Nor did I work every weekend. Sometimes I did. I worked that weekend when we found the psi.
The 8th question is, what advice would you give to future physicists or scientists? Do you ever think about that?
Yes. My advice would be: the most important thing is to enjoy what you do. That’s the primary requirement. Everything else can follow. In other words, to be able to work, maybe even be able to make a living at something you enjoy is so important, versus working at something that you don’t enjoy.
Did somebody tell this to you when you were younger and you followed it or you just naturally?
I discovered it.
The ninth question I already asked when we were talking about the discovery of dark energy. I was going to ask whether you had always been interested in astrophysics.
It wasn’t a passion. I was interested in what people were finding.
For example, when you were young and you had all those experiments in your room, were any of those with a telescope?
I did not have a telescope then. When my son was young we had a telescope and we looked at a few things. But I can say I was working in astrophysics before I made the switch.
My last question for the day is an open question. I wanted to ask is there anything you would like to say today that I neglected to ask. If yes, what, if not, is there anything specific you would like to talk about tomorrow? Because there’s so much of your work!
Well, we have to figure out what we want to do. Do we want to go through my entire career?
The answer’s yes? Alright, we can do that. I had, sort of the idea that all these talks which I gave could be the basis for a book sometime. That’s something to think about. I always felt that this is for students that one could do a popular version, something of this sort in a popular version that would be of general interest to the public.
And you already have ideas about that?
Well, I have ideas about the things I worked on. I didn’t work on everything in here. The things I worked on, yes I have ideas and I have basically, talks that I gave on all these fields.
Talks that are pretty general?
That were published in books and so on, and that I’ve written up. So that could be a basis. But, does that answer your question? Not really.
Do you think you would want to talk about those, your ideas. One of them would be perhaps even the book you’re talking about, include your drawings.
That’s a possibility that it could involve my drawings as well or at least some sample. But I have, let’s see. What do I have here? Now this for instance is the discovery, this is our discovery and Sam Ting’s discovery. This is Sam Ting and he discovered the J and we discovered the psi. This then is an article which I wrote at the time on our discovery of the psi, in some detail. Burt Richter wrote an article also about his view of things. That’s one paper in here which I gave you. And then there is, let’s see what this is. An article I wrote about the discovery of the charmed mesons. Here, for instance, this is the early work at the Bevatron. And as I said, I did the first… oops, what that? Oh, I see. Here, I discuss this event and discuss what I first did at the Bevatron. Literally, we went down to the Bevatron the day, the night it started running and exposed some emulsions there. Anyway, you’ll see what’s in here. We can discuss any one of these or however many we have a chance to discuss. Let me see, I may have to leave soon.
Yes, and the tape will be running out too. Shall we set a time to meet tomorrow?
They sometimes spring some meetings on me. As they did today, but today I didn’t go. Say 10 o’clock tomorrow?
You have a pass now? You can come up here? We can go from 10 till noon or some fraction of that and then again in the afternoon.
Should I go back and come back here?
You can stay here. There is a cafeteria. You can go to the library and amuse yourself.
Ok, great. That sounds fantastic. And I would like to buy this too.
Its fifteen dollars.
Is now a good time, shall I come back?
Now is fine. I’ll turn this off.